1. Field of the Invention
The present invention relates to a newly developed laparoscope apparatus constructed such that a cannula and an endoscope are detachably combined.
2. Description of the Prior Art
Laparoscope apparatuses are usually used as a basic tool for use in a laparoscopic surgery or the like and constructed such that inevitable information for diagnosing and treatment are given for an operator by visualizing the sight in abdominal cavity. Several kinds of apparatuses as improved in their visualization and operability were proposed heretofore.
FIG. 10a and FIG. 10b show external perspective views of a conventional laparoscope and a laparoscope apparatus respectively.
A laparoscope 102 of FIG. 10a comprises a lens and a hollow cannula 102a in which a light guide (not shown) comprised of plural optical fibers get through and constructed such that a light introduced from a light source port 101a is emitted at its tip end 102b of the cannula 102a for illuminating the object to be observed, i.e. an abdominal cavity so as to observe it from an eyeglass part 102d provided at its rear end 102c. 
According to such a laparoscope 102, abdominal cavity can be observed more clearly illuminating by the light guide. However, the angle scope is limited to the range from 70xc2x0 to 80xc2x0 because the cannula 102a has limitation not only in the length but also in its external diameter, therefore, a wide-angle image suitable for laparascopic surgery would not have been obtained.
A laparoscope apparatus 110 shown in FIG. 10b comprises a CCD (charge coupled device) camera 103 attached to an eyeglass part as shown in FIG. 10a as reference numeral 102d and constructed such that an image signal obtained by the CCD camera 103 is lead to a control box 105 for displaying on a screen such a CRT (cathode ray tube).
According to this apparatus, plural operators can observe the sight in abdominal cavity at the same time, thereby achieving improvement in convenience, however, the problem of the narrowness of angle of scope as above-mentioned still remains and can""t be solved in any way.
FIG. 11 is a partially cut-away front view of another embodiment of a conventional laparoscope.
The laparoscope 112 comprises a light source port 112a of a light guide, a tip end 112b, a rear end 112c and a eyeglass part 112d of a cannula 112a as like the laparoscope 102 shown in FIG. 10a and has a characteristic feature that plural rod lenses 112e which are excellent in an optical characteristics as lenses provided in the cannula 112a, therefore indeed the angle of scope has been enlarged to some extent, however, a desirable angle of scope hasn""t been obtained yet.
In addition, according to the conventional laparoscope as above-mentioned, a minute image of a subject would not have been also obtained clearly due to the fact that an image-picking means is attached to the cannula on its outside whereas the subject to be observed exists outward the cannula, therefore they locate apart from each other anyhow.
The present invention has been proposed to solve the above-mentioned problems.
Accordingly, it is an object of the present invention to provide a laparoscope apparatus which can obtain scope of wide angle and clear and minute image of sight in a cavity suitable for laparoscopic surgery or the like and which has also good facilities for operation and maintenance.
According to the present invention, a laparoscope apparatus for use in laparoscopic surgery or the like comprises a cannula with an inner hollow having therein a light guide means for introducing light to its tip end for illuminating an object to be observed. The cannula is sealed with transparent member at its tip end of the inner hollow for preventing of encroaching of water, preferably airtightly sealed. The laparoscope apparatus further comprises an endoscope capable of being pulled into and out from the inner hollow of the cannula, the endoscope having therein an image-picking up means with a wide-angle lens, and the image-picking up means being disposed close to the transparent member in the cannula.
The xe2x80x9ccannulaxe2x80x9d generally means an intubation for feeding liquid or air into an abdominal cavity for use in laparoscopic surgery or the like. However, in this specification, it includes a tubular member provided therein with a light guide for illuminating and used as a cylindrical container into which an endoscope is to be inserted. The endoscope generally includes a fiberscope, however in this specification, such an apparatus with an image-picking up means at its tip end constructed such that the image signal can be taken out of its rear end and both ends are connected to a flexible or a non-flexible cable is also included. xe2x80x9cThe image-picking up means being disposed close to the transparent memberxe2x80x9d means include such apparatus that the face of taking image contacts with the transparent member for observing.
It is a characteristic of the present apparatus that the endoscope is constructed such that it is detachable with the cannula. According to such a construction, they are combined with each other only when used and can be handled as separated members when cleaning and sterilizing it after use of them, and therefore, for instance, different sterilization suitable for each of the cannula and endoscope may be selectively applied.
Especially for the cannula, although it is required to be sterilized under strict state because it directly touches organs in abdominal cavity, according to the present apparatus, such a strict sterilization may be applied because the laparoscope housing an image-picking up means such a CCD camera can be easily detached from the cannula.
By the way, although an alcohol cleansing is a well known cleansing method, a general autoclave sterilization, EOG (ethylene oxide gas) sterilization which is effective at about 70xc2x0 C., and a plasma sterilization which is effective at about 40xc2x0 C. or 70xc2x0 C. may also be applied as a concrete sterilization method.
For example, one kind of sterilization may be applied to the endoscope and, while plural kinds of sterilization may be applied to the cannula. Further, it may be possible that alcohol is applied to only the endoscope but strict sterilization is applied to the cannula.
The endoscope to be combined with, or incorporated into the cannula is characterized in that the image-picking up means having a wide-angle lens is disposed close to the tip end of the cannula. According to such construction, a scope with wide angle can be obtained so that more detailed and clear image can be obtained, therefore, the endoscope more suitable for laparoscopic surgery or the like can be provided.
Further according to the laparoscope apparatus of the present invention, the light guide has a light emitting surface formed in such annular shape that it surrounds the transparent member and an annular diffusion cover is further provided at a part of the cannula which touches the light emitting surface for outwardly diffusing illuminating light emitted from the emitting surface of the light guide in the peripheral direction.
According to the apparatus, about the periphery of the tip end of the endoscope, namely an illuminating part to be observed can be uniformly illuminated because the annular diffusion cover is disposed at the tip end of the cannula, therefore illuminating light through the annular diffusion cover spreads widely in an abdominal cavity without locally concentrating in one direction so that halation caused when only specified part is strongly illuminated is effectively prevented and is also prevented from existing such a part where illumination is not applied.
Still further according to another embodiment of the laparoscope apparatus of the present invention, the light guide is constructed such that on its end side of its annular diameter is gradually enlarged in the direction toward the front of the cannula.
According to the embodiment, since the annular shape constituting an illuminating part is constructed such that it is enlarged outwardly around the endoscope housed in the cannula, in other word, the annular diameter is gradually enlarged toward the end of the cannula, halation can be effectively prevented even when the light is annually emitted in parallel.
Moreover, in another embodiment of the present invention, the annular diffusion cover is comprised of an annular concave lens.
According to the embodiment, light emitted from the light guide is reflected by the annular lens or the light guide prism provided at the tip end of the cannula respectively in each embodiment and is outwardly directed in the peripheral direction but is not directed in the front direction. Therefore, light emitted from the light guide is prevented from concentrating on one part and therefore is uniformly and widely diffused by the concave lens or the guide prism so that halation as above-mentioned can be also effectively prevented. Hence, the apparatus may be more suitable for picking up the image of the sight in abdominal cavity at wide-angle.
Still further, according to other embodiment of the present invention, the light guide prism has a light diffusion surface at least one end of either its incident or its emission end.
According to another embodiment of the present invention, the endoscope can be separated from and incorporated into the cannula by pulling it into or pulling out from the cannula by easy manual operation: wherein one embodiment is characterized in that the cannula further comprises an installation means having an association hole into which the endoscope is inserted and the endoscope is attached with a resiliently deformable fitting member, the fitting member being resiliently deformed so as to allow the detachment of the endoscope from the cannula, when the endoscope is pulled into and from the association hole of the installation portion and, whereas in another embodiment simultaneously proposed, the cannula further comprises an installation means having plural association grooves and an association hole into which the endoscope is inserted and the endoscope is attached with a fitting member with an association claw, the fitting member being constructed such that the association claw is engaged with any of the association grooves by inserting the endoscope attached with the fitting member into the association hole with the association claw opened and thereafter closing the association claw.